1. Field of the Invention
The present invention relates to a thermo-sensitive semiconductor device, such as positive and negative temperature coefficient thermistor devices or the like. More particularly, the invention relates to an electronic part having lead terminals connected to a thermo-sensitive semiconductor device which are coated in an insulating manner.
2. Description of the Related Art
An explanation will now be provided of a conventional electronic part having lead terminals which are coated in an insulating manner with reference to FIGS. 5-7.
As illustrated in FIG. 5, an electronic part having lead terminals which are coated in an insulating manner (hereinafter referred to as "insulation-coated lead terminals") is formed by the following process. Insulation-coated lead terminals 2, having both ends stripped of unnecessary insulating coatings, are directly connected by use of solder H or the like to an electronic part unit 1, i.e., a thermo-sensitive semiconductor device, such as a positive or negative temperature coefficient thermistor or the like. Then, the electronic element part unit 1 is coated in an insulating manner.
Alternatively, as shown in FIG. 6, a semi-finished product denoted by 5 comprising the electronic part element unit 1 which is coated in an insulating manner is obtained by the following process. Lead terminals 3 without insulating coatings (hereinafter simply referred to as "the lead terminals") are directly connected to the unit 1. The unit 1 and the portions of the lead terminals 3 adjacent to the unit 1 are immersed in a molten insulating coating 4. Subsequently, as shown in FIG. 7, insulating tubes 6 are fit around the lead terminals 3 of the semi-finished product 5, thereby obtaining an electronic part having the lead terminals which are thus coated in an insulating manner.
The electronic parts constructed as described above are formed by connecting the lead terminals 2 or 3 to the unit 1. The lead terminals 2 and 3 are insulated before or after the connecting operation, respectively.
However, the electronic parts provided with insulation-coated lead terminals constructed as described above encounter the following problems. It is difficult to strip the insulating coatings from the electronic parts, and also hard to connect the terminals to each of the electronic part element units. The formation of the lead terminals themselves is difficult. Additionally, a method of fitting the insulating tubes around the lead terminals increases the number of steps in the manufacturing process. It is also difficult to maintain the pitch of longer lead terminals constant.